The effects of selective feedback on visual search target detection

The current study investigated the effect of a retraining intervention that utilises selective feedback, in which feedback is only provided for misses, on target detection performance in low prevalence settings. Fifty-one participants (34 female) aged 18-50 years (M =26.57 years, SD =6.19 years) were randomly allocated to either the control condition, where they received no feedback, the full feedback condition, where they received feedback on all training trials, or the selective feedback condition, where they only received feedback when they missed a target on a training trial. Participants completed a visual search task that required them to look for a knife in x-ray images of luggage. The study consisted of alternating long, low prevalence 'on the job' blocks and brief, higher prevalence 'training' blocks. As expected, the selective feedback retraining procedure led to a significantly less conservative criterion than full feedback and no feedback. This translated into a significantly greater proportion of false alarms than full feedback and no feedback, and a meaningful, but non-significant, increase in hits compared to the control condition. Unexpectedly, however, there was no effect of feedback on response times. Such findings provide valuable information for the low prevalence setting of airport luggage screening.